The (A) bitcoin system created (B) in 2009 by an enigmatie (C) person named (D) Satoshi Nakamoto

A. unskilled 

B. ill-educated 

C. unimpaired 

D. unqualified 

A. commitment 

B. obligation 

C. assignment 

D. responsibility 

A. of 

B. on 

C. for 

D. from 

A. Once annoying by the boys' behaviour 

B. Annoyed by the boys' behaviour 

C. Having annoyed behaviour by the boys 

D. She annoyed by the boys' behaviour uncommon

A. Peter told Mary to believe in what the boy said

B. Peter said that Mary believed in what the boy had said

C. Peter asked Mary whether she believed in what the boy says

D. Peter asked Mary if she believed in what the boy said

A. voluntarily 

B. volunteer 

C. volunteers 

D. voluntary 

A. Tom was sorry that he has left the tickets at home

B. Tom wishes he hadn't left the tickets at home

C. Tom regrets not leaving the tickets at home

D. Tom regrets to leave the tickets at home